noun

• (uncountable) A chemical, such as sodium hypochlorite or hydrogen peroxide, or a preparation of such a chemical, used for disinfecting or whitening.
• (countable) A variety of bleach.

verb

• (transitive) To treat with bleach, especially so as to whiten (fabric, paper, etc.) or lighten (hair).
  "Candifacio, to make whyte, to bleache, to make to glowe lyke a burnyng cole."
• (intransitive) To be whitened or lightened (by the sun, for example).
  "The white sheet bleaching on the hedge, With heigh! the sweet birds, O, how they sing!"
• (intransitive, biology, of corals) To lose color due to stress-induced expulsion of symbiotic unicellular algae.
  "Once coral bleaching begins, corals tend to continue to bleach even if the stressor is removed."
• (transitive, figurative) To make meaningless; to divest of meaning; to make empty.
  "semantically bleached words that have become illocutionary particles"

adj

• (archaic) Pale; bleak.

noun

• (obsolete) A disease of the skin characterized by hypopigmentation and itching, believed in the 17th century to be a form of leprosy.